CN113086184B

CN113086184B - Tandem distributed electric propulsion coaxial duct vertical take-off and landing aircraft

Info

Publication number: CN113086184B
Application number: CN202110440034.2A
Authority: CN
Inventors: 赵龙飞; 焦宗夏; 胡炯; 郑杨; 王泽浩
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2021-04-23
Filing date: 2021-04-23
Publication date: 2023-03-17
Anticipated expiration: 2041-04-23
Also published as: CN113086184A

Abstract

Embodiments of the present disclosure disclose a tandem distributed electrically-propelled coaxial ducted VTOL aerial vehicle. One specific implementation mode of the aircraft comprises an aircraft body, a first wing, a second wing and a power assembly, wherein the bottom of the aircraft body is formed by tilting the middle part towards the advancing direction and away from the advancing direction and is used for realizing the rolling type take-off and landing along the outer edge of the aircraft body; the first wing is symmetrically connected to two sides of a first end of the machine body facing to the traveling direction, wherein the first wing is provided with a dihedral angle and a forward sweep angle; the second wing is symmetrically connected to two sides of a second end of the machine body, wherein the second end deviates from the traveling direction, and the second wing is provided with a dihedral angle and a sweepback angle; a power assembly is disposed into the airframe for powering the first wing and the second wing. The embodiment can enhance the terrain adaptability of the aircraft and reduce the influence of the environment on the take-off and landing of the aircraft.

Description

Tandem distributed electric propulsion coaxial duct vertical take-off and landing aircraft

Technical Field

The embodiment of the disclosure relates to the technical field of aircrafts, in particular to a tandem distributed electric propulsion coaxial duct vertical take-off and landing aircraft.

Background

The VTO (Vertical Take-Off and Landing) aircraft has the characteristics of efficient cruise with fixed wings and runway-free Vertical Take-Off and Landing of helicopters, and has wide application prospect in the fields of complex environment battles, future urban traffic, transportation and the like.

The tilting type vertical take-off and landing aircraft can adjust the thrust direction of an engine through an actuator and a transmission mechanism so as to take off and land.

The tailstock type vertical take-off and landing aircraft adopts a machine tail land type vertical take-off and landing, and hovering and cruising mode switching is realized through a tilting machine body in the air.

The composite power type vertical take-off and landing aircraft is provided with two sets of power systems of hovering and flat flying. When taking off and landing or hovering, a multi-rotor power mode is adopted; and a fixed wing aircraft propulsion mode of horizontal installation is adopted during cruising.

However, in practical applications, the following technical problems often exist in the aircraft:

first, there are problems of heavy structure, dead weight, and difficulty in control.

Second, the transition from hover to cruise is relatively long, otherwise uncontrollable conditions may be encountered, making the transition difficult to shorten.

Thirdly, the requirement on the flatness of the take-off and landing site is high, and the take-off and landing are in a tipping risk under the complex terrain or meteorological conditions.

Thus, the applications and the types of tasks that can be performed by the aircraft are limited.

Disclosure of Invention

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

Some embodiments of the present disclosure address one or more of the above technical problems in the background section by providing a tandem distributed electrically-propelled coaxial ducted VTOL aerial vehicle.

The aircraft comprises an aircraft body, a first wing, a second wing and a power assembly, wherein the bottom of the aircraft body is formed by tilting the middle part towards the advancing direction and away from the advancing direction and is used for realizing the rolling type take-off and landing along the outer edge of the aircraft body; the first wing is symmetrically connected to two sides of a first end of the machine body facing to the traveling direction, wherein the first wing is provided with a dihedral angle and a forward sweep angle; the second wing is symmetrically connected to two sides of a second end of the machine body, wherein the second wing deviates from the traveling direction, and is provided with a dihedral angle and a sweepback angle; the power assembly is arranged in the machine body and used for providing power for the first wing and the second wing.

In some embodiments, the first wing and the second wing each include a plurality of connected ducted wing units, the ducted wing units including a ducted body for housing the propeller assembly and a propeller assembly disposed toward a direction of travel for providing thrust.

In some embodiments, the first wing and the second wing further comprise a control surface pivotally connected to an end of the ducted body facing away from the direction of travel, the control surface rotating to change the flow area of the ducted body to adjust the thrust magnitude and direction of the first wing and the second wing in an operational state.

In some embodiments, the body includes a first section, a middle section, and a second section, wherein in a parked state, the middle section engages a parking surface, the first wing is lower than the second wing, and a chord direction of the first wing forms an acute angle with the parking surface; in a rolling takeoff state, the first wing forms a head raising force arm, the first section and the middle section are raised along the outer edge of the aircraft body under the matching of the control surface, and the second section is jointed with the parking surface; in the process from the rolling takeoff state to the cruising state, a pitching moment is formed under the comprehensive adjustment of the thrust difference of the first wing and the second wing and the control surface, so that the aircraft is lowered, and the included angle between the chord direction of the first wing and the horizontal plane is further reduced.

In some embodiments, when the control surfaces of the first wing and the second wing deflect, a horizontal component or a vertical component is generated on the first wing and the second wing, and the aircraft is driven to move horizontally or longitudinally so as to resist crosswind or change the flight height.

In some embodiments, the bottom of the machine body is further symmetrically provided with ground gripping members at intervals along the length direction of the machine body, and the ground gripping members are used for increasing the friction force with the parking surface.

In some embodiments, the power assembly includes a first engine for driving the first wing and the second wing to provide thrust, a second engine for driving a generator to generate electric energy to drive the first engine, and an intake duct provided to the intake duct of the fuselage adjacent to the second wing to allow air to enter the second engine.

In some embodiments, the first engine is an electric engine; the second engine includes at least one of: diesel engines, gasoline engines, jet engines.

In some embodiments, the first wing further comprises a retractable cabin and a docking member disposed within the cabin, wherein in a docked state, the cabin is extended and the docking member and the central section engage the docking surface.

In some embodiments, the enclosure comprises at least one of: wheel cabin, buoyancy cabin.

In some embodiments, two ends of the second wing are further provided with winged knives.

The above embodiments of the present disclosure have the following advantages: by the tandem distributed electrically-propelled coaxial ducted VTOL aerial vehicle of some embodiments of the present disclosure, control of the aerial vehicle can be facilitated as compared to an associated aerial vehicle. Specifically, the related tilting type vertical take-off and landing aircraft is complicated in structure, and the reason that the aircraft is heavy and difficult to control is that: the tilting type vertical take-off and landing aircraft needs to control the thrust directions of the actuators and the transmission mechanisms to adjust the engines, so that the weight and the control inertia of the aircraft are increased. The reason why the tailstock type vertical take-off and landing aircraft has higher requirements on wind speed and take-off and landing sites is that: the undercarriage of the tail seat type aircraft restrains the aircraft from being in a posture that the aircraft body is vertical to the ground when the aircraft is parked, the gravity center of the aircraft in a shutdown state is higher, the wing surface is vertical to the ground, and the windward area is larger; during take-off and landing, the aircraft is therefore prone to tipping over from crosswind disturbances, making control difficult.

Based on this, the tandem distributed electric propulsion coaxial duct VTOL aircraft of some embodiments of this disclosure, first wing and second wing are connected to the both ends of organism symmetrically. The first wing is provided with a down-camber angle and a forward-sweep angle, and the second wing is provided with an up-camber angle and a backward-sweep angle. And because the first wing and the second wing are arranged to have a dihedral angle and a dihedral angle, firstly, the height of the airplane body can be shortened, and the lift-drag ratio in a cruising state can be improved. And secondly, the distance between the propeller shafts of the first wing and the second wing is increased, so that the control force of the aircraft is improved, and the aircraft can safely fly under the complex meteorological condition. Thirdly, the influence of the wake generated by the first wing on the second wing is reduced, and meanwhile, a control moment is formed in the hovering stage. And because the first wing and the second wing are set to have a forward sweep angle and a backward sweep angle, the longitudinal size of the aircraft can be increased, the trim capability of the aircraft is further improved, and the control performance is improved.

In addition, the tandem distributed electric propulsion coaxial duct vertical take-off and landing aircraft of some embodiments of the present disclosure has a bottom portion of the airframe formed by a middle portion tilted toward and away from a direction of travel. During taking off and landing, the aircraft rolls along the outer edge of the aircraft body to take off and land, so that the attitude of the aircraft is prevented from being changed violently from hovering to taking off and landing. Meanwhile, even when the aircraft takes off and lands on the ground or water with a certain gradient and unevenness, the aircraft can realize the smoothness of the taking off and landing process and the stability of the shutdown through the curved surface at the bottom of the aircraft body.

Drawings

The above and other features, advantages, and aspects of embodiments of the present disclosure will become more apparent by referring to the following detailed description when taken in conjunction with the accompanying drawings. Throughout the drawings, the same or similar reference numbers refer to the same or similar elements. It should be understood that the drawings are schematic and that elements and features are not necessarily drawn to scale.

FIG. 1 is a structural schematic diagram of some embodiments of a tandem distributed electrically-propelled coaxial ducted VTOL aerial vehicle according to the present disclosure;

FIG. 2 is a schematic top view of some embodiments of a tandem distributed electrically-propelled coaxial ducted VTOL aerial vehicle according to the present disclosure;

FIG. 3 is a left side view of some embodiments of a tandem distributed electrically-propelled coaxial ducted VTOL aerial vehicle according to the present disclosure;

FIG. 4 is a schematic illustration of a take-off and landing process for a tandem distributed electrically-propelled coaxial ducted vertical take-off and landing aircraft according to the present disclosure;

FIG. 5 is a schematic illustration of some embodiments of direct force control of a tandem distributed electrically-propelled coaxial ducted VTOL aerial vehicle according to the present disclosure;

FIG. 6 is a schematic illustration of further embodiments of direct force control for a tandem distributed electrically-propelled coaxial ducted VTOL aircraft according to the present disclosure.

Detailed Description

Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While certain embodiments of the present disclosure are shown in the drawings, it is to be understood that the disclosure may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided for a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and the embodiments of the disclosure are for illustration purposes only and are not intended to limit the scope of the disclosure.

It should be noted that, for convenience of description, only the portions related to the related invention are shown in the drawings. The embodiments and features of the embodiments in the present disclosure may be combined with each other without conflict.

It should be noted that the terms "first", "second", and the like in the present disclosure are only used for distinguishing different devices, modules or units, and are not used for limiting the order or interdependence relationship of the functions performed by the devices, modules or units.

It is noted that references to "a", "an", and "the" modifications in this disclosure are intended to be illustrative rather than limiting, and that those skilled in the art will recognize that "one or more" may be used unless the context clearly dictates otherwise.

The names of messages or information exchanged between devices in the embodiments of the present disclosure are for illustrative purposes only, and are not intended to limit the scope of the messages or information.

The present disclosure will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

Referring first to fig. 1 and 2, fig. 1 is a schematic structural view of some embodiments of a tandem distributed electrically-propelled coaxial ducted VTOL aerial vehicle according to the present disclosure. Fig. 2 is a schematic top view of some embodiments of a tandem distributed electrically-propelled coaxial ducted VTOL aircraft according to the present disclosure. As shown in fig. 1 and 2, the aircraft includes a body 4, a first wing 2, a second wing 5, and a power assembly (not shown).

Specifically, the first wing 2 is symmetrically connected to a first end (lower end in fig. 1) of the body 4. The first end of the airframe 4 may be the forward end of the aircraft while traveling. The second wing 5 is symmetrically connected to a second end (upper end in fig. 1) of the body. The second end of the airframe 4 may be the aft end of the aircraft while traveling.

The first wing 2 and the second wing 5 may be conventional wings and tail wings. Open propellers are arranged on the wings and the empennage.

Optionally, as shown in fig. 1, the first wing 2 and the second wing 5 may further comprise four connected ducted wing units (not shown). The ducted wing unit comprises a ducted body and a propeller assembly 9. The ducted body is for housing a propeller assembly 9. The propeller assembly 9 may be arranged towards the direction of travel to provide thrust in the operational state. It should be noted that, although fig. 1 shows 4 ducted wing units as an example. However, the number of the ducted wing units is not unique, and different numbers of ducted wing units can form wings with different aspect ratios. The number of the ducted wing units can be adjusted by those skilled in the art according to actual conditions. Under the working condition, the plurality of duct wing units can generate power, so that the power of the aircraft is more stable. The propeller assembly 9 may be a fixed-pitch propeller, a variable-pitch propeller, or a double-layer propeller. The person skilled in the art can make the selection on the basis of common general knowledge or prior art.

Further, on the end of the ducted bodies of the first wing 2 and the second wing 5 facing away from the direction of travel, a control rudder (not shown in the figures) may also be pivotally connected. Further, in the operating state, the flow area and the flow direction of the ducted body can be changed by controlling the rotation of the control surface with respect to the ducted body. And further adjust the thrust direction and magnitude of the first wing 2 and the second wing 5, so as to adapt to the flight speed or thrust requirements of the aircraft at different stages. As an example, the control rudder surfaces can symmetrically or asymmetrically block the channel of the ducted body under the control of the motor or the steering engine, so as to change the direction of thrust generated by the propeller assembly or seek the optimal operating point of the ducted body at different flight speeds. Those skilled in the art can make adjustments according to actual situations or experiments. In particular, the control surface may be pivotally connected with the culvert body by means of hinges or the like, so as to rotate under the control of a motor or a steering engine to shade the culvert body. Further, the control surface can also change the slipstream direction of the propeller assembly after rotating, so that the thrust direction of the first wing and the second wing can be changed. As an example, the above-mentioned control surface may be two plate-shaped members, the upper edge of one plate-shaped member being hinged with the upper edge of the duct body and the lower edge of the other plate-shaped member being hinged with the lower edge of the duct body. Under the control of the motor or the steering engine, the two plate-shaped members can be turned over up and down along the pivot shaft, so that the flow area of the duct main body is changed. At the same time, the two plate-like members, after rotation, form a channel extending the through-flow length of the stent body. The direction of the channels is different according to the rotation direction of the plate-shaped component, and the through-flow direction of the gas can be guided, so that the thrust direction can be adjusted.

The first wing 2 is provided with a dihedral and a forward sweep angle, and the second wing 5 is provided with a dihedral and a backward sweep angle. Therefore, the height of the body can be shortened, and the lift-drag ratio in the cruising state can be improved. In addition, the distance between the propeller shafts of the first wing and the second wing is also increased, so that the control force of the aircraft is improved, and severe weather is overcome. The influence of the wake generated by the first wing 2 on the second wing 5 is further reduced while forming a control moment during the hovering phase. And because the first wing 2 and the second wing 5 are set to have a forward sweep angle and a backward sweep angle, the longitudinal size of the aircraft can be increased, the trim capability of the aircraft is further improved, and the control performance is improved.

In some embodiments, the body 4 may have a load compartment for accommodating a driver, cargo, and the like. The bottom of the machine body 4 is formed by tilting the middle part towards and away from the direction of travel. In the taking-off and landing process, the first aircraft wing 2 provides lift force under the control of the control surface, so that the front end of the aircraft is lifted, the arc-shaped structure of the bottom 3 of the aircraft body is gradually separated from the ground, and finally the aircraft is in a vertical state. The arc-shaped arrangement of the bottom 3 of the machine body enables rolling and lifting to be smoother. Meanwhile, the violent change of the attitude of the aircraft from hovering to taking off and landing is relieved.

Turning next to fig. 3 and 4, fig. 3 is a left side view of some embodiments of a tandem distributed electrically-propelled coaxial ducted VTOL aircraft according to the present disclosure. FIG. 4 is a schematic illustration of a takeoff and landing procedure of a tandem distributed electrically-propelled coaxial ducted VTOL aircraft according to the present disclosure. As shown in fig. 3 and 4, the body bottom 3 may optionally include a first section 31, a middle section 32, and a second section 33. In particular, when the aircraft is parked on a parking surface, the central section 32 of the body 4 engages the parking surface. The parking surface may be a floor, a slope, or the like. At this time, the first wing 2 may be lower than the second wing 5. The axial direction of the duct body of the first wing 2 and the duct body of the second wing 5 is raised toward one end in the traveling direction, in other words, the chord direction of the first wing and the chord direction of the second wing form an acute angle with the parking plane. So that when the first wing 2 is in operation, the thrust generated by the propeller assembly 9 acts on the ground, generating a stronger reaction force. Further, the loss of thrust can be reduced by the control surface. In the roll-off state, the first wing 2 provides thrust to lift the first section 31 and the middle section 32 along the outer edge of the aircraft body, and the second section 33 is engaged with the landing surface. The aircraft gradually enters a vertical position.

Optionally, in order to increase the friction between the body 4 and the ground, so that the aircraft can be parked and landed on a slope and unevenness of the ground, a ground-grasping member (not shown) for increasing the friction and adhesion between the body 4 and the ground can be provided on the bottom 3 of the body. The ground engaging member may be a grapple or the like. Reinforcing ribs may be provided on the machine body bottom 3, and ground-grasping members may be provided on the reinforcing ribs. The grip members may be provided at regular intervals along the longitudinal direction of the body 4. Alternatively, the above-described gripping members may be arranged such that the interval in the width direction of the body 4 gradually decreases from the first section 31 to the second section 33. Therefore, in the rolling takeoff process, the friction torque between the aircraft and the ground can be gradually reduced, and the power consumption during takeoff is reduced. In addition, the aircraft takes off under the condition of unfavorable wind direction, and gradually carries out course adjustment along with the reduction of friction torque.

The power assembly may include a first engine. The first engine is used for driving the first wing and the second wing. The first engine may be an electric engine. Optionally, the power assembly may further include a second engine, which may be a diesel engine, a gasoline engine, or the like. At the same time, an intake duct 6 is provided in the body, close to the second wing 5, so as to supply air to the second engine. The second engine is used for driving the generator to work and further providing electric energy for the first engine. Thereby effectively improving the endurance of the aircraft. The power assembly may further include an exhaust duct, which may be provided into the duct body of the second airfoil. The axial direction of the exhaust duct is consistent with the axial direction of the propeller assembly. Therefore, smooth exhaust of the second engine under any flight attitude is realized.

Referring back to fig. 1, the first wing 2 is further provided at both ends thereof with a retractable cabin 1 and a parking member 11 provided to the cabin. In the parking position, the cabin 1 is extended and the parking structure 11 and the central section 32 engage the parking surface. The cabin body 1 can be a wheel cabin or a buoyancy cabin. The parking surface may be the ground or the water surface. Parking member 11 may be a wheel, a pontoon. So that the aircraft can take off and land on the water surface or on the ground. Thereby enhancing the terrain adaptability and application site of the aircraft. Thereby completing a wider variety of tasks. Meanwhile, when the tail part of the aircraft is pulled up by external force, the parking member 11 can enable the aircraft to move freely like a trailer, and the movement mode can be used in the ground dragging and transporting process of the aircraft.

Optionally, winged knives 8 can be further arranged at two ends of the second wing 5, so that a protection effect can be provided for the second wing 5, and the problem that the aircraft rubs on the ground when landing is avoided. Structurally, the lateral area of the rear part of the aircraft is increased, and the course stability is improved.

Finally, the takeoff process of the aircraft is explained in connection with fig. 4. Fig. 4 shows, from right to left, four states of the aircraft during takeoff, namely a parked state, a roll takeoff state, a vertical hover state, a transition state, and a cruise state. In the parked state, the parking member and the middle section of the airframe contact the ground, supporting the aircraft. At this time, the chord direction of the first wing forms an acute angle with the parking surface. When the aircraft enters a rolling takeoff state from a parking state, the propeller assembly of the first wing rotates to form thrust, so that a thrust difference is generated between the propeller assembly and the second wing, and a head raising force arm is formed by the distance between a thrust line of the thrust formed by the first wing and a parking surface. The product of the thrust of the first wing and the force arm is a head-up moment. It should be noted that, during the raising process, the control surface of the first wing may move in coordination, for example, under the action of a motor or a steering engine, the control surface rotates along the pivot shaft, so that the airflow passing through the ducted body is deflected downward after passing through the control surface, and the airflow ejected from the first wing is deflected downward, thereby increasing the moment arm. Thereby improving the head raising moment and leading the head raising process to be quicker and more controllable.

Gradually, the aircraft gradually turns over along the arc-shaped structures of the middle section and the second section of the aircraft body, and finally breaks away from the ground to enter a hovering state.

In the hovering state, the propeller planes of the propeller assemblies of the first wing and the second wing are approximately perpendicular to the horizontal plane. During hovering, the aircraft deflects the slipstream of the propeller to obtain additional control torque by controlling the rotation speed difference and the pitch difference of the propeller components or by controlling the control surface of the first wing or the second wing.

In the transition process of the related aircraft, the lift force is formed by the vertical component of the thrust of the power system and the lift force of the wings, and the transition process and the power tilting of the aircraft must accord with a certain rule so as to ensure that the lift force of the aircraft can be in smooth transition before and after the stall point of the wings, so that the stability and the rapidity of the transition process are greatly restrained by the tilting mechanism.

The aircraft disclosed by the invention can form pitching moment to enable the aircraft to lower the head under the comprehensive regulation of the thrust difference of the first wing and the second wing and the control surface, namely, the included angle between the chord direction of the first wing and the horizontal plane is reduced, so that the aircraft enters a transition state from a hovering state to a cruising state. Specifically, in the transition state, the thrust of the second wing is adjusted to be larger than that of the first wing, and then a pitching moment is formed to enable the aircraft to bow. In the process, the control surface of the second wing rotates, so that the airflow of the duct main body of the second wing gradually tends to be horizontal by downward deflection after passing through the control surface. It is noted that the hover process need not necessarily exist in order to allow for the rapidity of aircraft takeoff and landing. The aircraft can also directly enter a transition state after leaving the ground, and immediately accelerate and fly forwards. However, since the wings are in the stall state in the transition state and cannot generate enough lift, directly entering the transition state requires the aircraft power system to output a large thrust to maintain the balance between the aircraft lift and gravity.

And finally, continuously reducing the included angle between the chord direction of the first wing of the aircraft and the horizontal plane, recovering the flow around the wing, entering a state of normally generating lift force, and enabling the aircraft to enter a cruising state. In the cruise state, the power assembly provides forward pulling force, and the first wing and/or the second wing generate lifting force to efficiently cruise in a fixed wing airplane mode.

The landing process of an aircraft is the reverse of the takeoff process. In the cruising state of the aircraft, the thrust is reduced, the included angle between the chord direction of the wing and the horizontal plane is increased, and the aircraft enters a transition state. In the transition state, the aircraft speed gradually decreases to zero, and the hovering state is entered. The aircraft then continues to lower to ground to the aft of the fuselage or to the curved blade on the second wing to ground. And then the aircraft rolls to a stopping angle along the curved surface of the belly mainly by relying on the thrust of the first wing and the deflection of the control plane. It is noted that the aircraft angle of shutdown may vary over a range. That is to say, the aircraft can land and stably park on the ground with certain gradient. The maximum ground slope limit will be related to the specific design of the belly curve. The person skilled in the art can make adjustments according to the actual situation.

It is also noteworthy that the ground clearance and grounding of the aircraft of the present disclosure does not necessarily require that the aircraft be maintained perpendicular to the ground during take-off and landing. For example, in the case of high winds, the blade plane of the propeller assembly needs to be at an angle to the ground when the aircraft is suspended, and the horizontal component of the propeller assembly thrust is used to resist horizontal winds. With current helicopters or multi-rotor aircraft, since their landing gear determines a fixed parking angle, it is necessary to transit from a non-perpendicular hovering angle to a perpendicular parking angle at the instant of grounding, with the risk of bumping or tipping over. The aircraft disclosed by the invention can be grounded through a hovering angle naturally formed in wind and rolled to a stopping angle.

The aircraft disclosed can generate a direct force vector control effect by controlling the cooperation of the control surface, the position or flight track of the aircraft can be changed under the condition that the attitude of the aircraft is not changed, and the maneuverability and the anti-interference capability of the aircraft can be greatly improved by the aid of the characteristics. Next, description will be made with reference to fig. 5. FIG. 5 is a schematic diagram of some embodiments of direct force control of a tandem distributed electrically-propelled coaxial ducted VTOL aerial vehicle according to the present disclosure. As shown in fig. 5, the aircraft is in a hovering state. When the aircraft needs to resist the crosswind in the horizontal direction, the control surfaces of the first wing and the second wing can deviate from the crosswind to deflect at the same time, so that the slipstream of the propeller assemblies of the first wing and the second wing is deflected to the same direction, and therefore under the condition that no additional attitude control moment is generated, a horizontal force component is directly generated on the first wing and the second wing to drive the aircraft to move horizontally, and the interference of the crosswind is further resisted. The direct power maneuverability can ensure that the aircraft can obtain better crosswind resistance in the taking-off and landing processes, and the stable attitude angle is kept for grounding; the precision of the take-off and landing attitude, the track and the grounding point of the aircraft can be improved. So that the device can be operated in a narrow take-off and landing place. Meanwhile, the dependence of horizontal movement on the horizontal component of the propulsion system is avoided, and the installed power requirement is reduced.

By combining the direct force vector control scheme and the aircraft take-off and landing mode, the technical problems that the long hovering-cruising transition process is needed and otherwise an uncontrollable state is caused, so that the transition process is difficult to shorten and the technical problems that the requirement on the flatness of a take-off and landing site is high and the take-off and landing are in rollover risk under the complex terrain or meteorological conditions can be solved.

Referring next to fig. 6, fig. 6 is a schematic illustration of further embodiments of direct force control for a tandem distributed electrically-propelled coaxial ducted VTOL aircraft according to the present disclosure. As shown in fig. 6, the aircraft is in cruise phase. Under the control of the same-direction deflection of the control surfaces of the first wing and the second wing, the jet flow direction of the propeller assembly deflects upwards or downwards at the same time, and aerodynamic force in the vertical direction is formed on the premise of not generating extra attitude control moment, so that the flying height of the aircraft can be changed quickly.

The foregoing description is only exemplary of the preferred embodiments of the disclosure and is illustrative of the principles of the technology employed. It will be appreciated by those skilled in the art that the scope of the invention in the present disclosure is not limited to the specific combination of the above-mentioned features, but also encompasses other embodiments in which any combination of the above-mentioned features or their equivalents is made without departing from the spirit of the invention. For example, the above features and (but not limited to) the features disclosed in this disclosure having similar functions are replaced with each other to form the technical solution.

Claims

1. A tandem distributed electric propulsion coaxial duct vertical take-off and landing aircraft comprises an aircraft body, a first wing, a second wing and a power assembly, wherein,

the bottom of the machine body is formed by tilting the middle part towards the advancing direction and away from the advancing direction and is used for realizing the rolling type lifting along the outer edge of the machine body;

the first wing is symmetrically connected to two sides of a first end of the machine body facing to the traveling direction, wherein the first wing is provided with a dihedral angle and a forward sweep angle;

the second wing is symmetrically connected to two sides of a second end of the machine body, wherein the second wing deviates from the traveling direction, and is provided with a dihedral angle and a sweepback angle;

the power assembly is arranged in the machine body and is used for providing power for the first wing and the second wing;

the first wing and the second wing respectively comprise a control surface and a plurality of connected ducted wing units, each ducted wing unit comprises a ducted main body, the control surfaces are two plate-shaped members, the upper edge of one plate-shaped member is hinged with the upper edge of the ducted main body, the lower edge of the other plate-shaped member is hinged with the lower edge of the ducted main body, and the two plate-shaped members are turned over up and down along a pivot shaft under the control of a motor or a steering engine so as to change the flow area of the ducted main body;

the aircraft body comprises a first section, a middle section and a second section, wherein in a parking state, the middle section is jointed with a parking surface, the first wing is lower than the second wing, and an acute angle is formed between the chord direction of the first wing and the parking surface; in a rolling takeoff state, the first wing forms a head raising force arm, the first section and the middle section are lifted along the outer edge of the aircraft body under the matching of the control surface, and the second section is jointed with the parking surface; in the process from the rolling takeoff state to the cruising state, a pitching moment is formed under the comprehensive adjustment of the thrust difference of the first wing and the second wing and the control surface, so that the aircraft is lowered, and the included angle between the chord direction of the first wing and the horizontal plane is further reduced.

2. The aircraft of claim 1 wherein the ducted wing units comprise a ducted body and a propeller assembly, wherein the ducted body is configured to house the propeller assembly, the propeller assembly being disposed toward a direction of travel for providing thrust.

3. The aircraft of claim 2, wherein the control surface is pivotally connected to an end of the ducted body facing away from the direction of travel, the control surface rotating to change the flow area of the ducted body to adjust the magnitude and direction of thrust of the first and second airfoils in an operational state.

4. The aircraft of claim 1, wherein when the control surfaces of the first wing and the second wing deflect, a horizontal component or a vertical component is generated on the first wing and the second wing, and the aircraft is driven to move horizontally or longitudinally to resist crosswind or change flying height.

5. The aircraft of claim 1, wherein the bottom of the airframe is further symmetrically spaced along the length of the airframe with ground-engaging members for increasing friction with the landing surface.

6. The aircraft of claim 1, wherein the power assembly comprises a first engine for driving the first wing and the second wing to provide thrust, a second engine for powering an electrical generator to generate electrical energy to drive the first engine, and an intake duct disposed to an intake duct of the fuselage proximate the second wing to allow air to enter the second engine.

7. The aircraft of claim 6, wherein the first engine is an electric engine; the second engine includes one of: diesel engines, gasoline engines, jet engines.

8. The aircraft of claim 5, wherein the first wing is further provided at both ends with a retractable cabin and parking members provided into the cabin, the cabin extending in a parked state, the parking members and the middle section engaging the parking surfaces.

9. The aircraft of claim 8, wherein the nacelle comprises at least one of: wheel cabin, buoyancy cabin.

10. The aircraft of claim 9, wherein the second wing is further provided with wingknives at both ends.